Locomotive power reverse gear



0d. 15; 1935. G. H. zoucK LOCOMOTIVE POWER-REVERSE GEAR Filed April 19,1933 2 Sheets-Sheet 1 Oct. 15, 1935.

G. H. ZOUCK LOCOMOTIVE POWER REVERSE GEAR Filed April 19, 1935 2Sheets-Sheet 2 33 40 37 T 43, L I 39 as 4 5 as J 56 5 v i H? i 35 H8 15I /7 l5 f Patented Oct. 15, 1935 UNITED STATES PATENT OFFICE LOCOMOTIVEPOWER REVERSE GEAR Application April 19, 1933, Serial No. 666,795

. 1 Claim.

This invention relates to power reverse gears of the fluid pressureoperated type. The invention is especially concerned with a fluidpressure supply and control system for a reverse gear including twosources of fluid pressure, such as 5 steam and air which are adapted tobe used in the gear alternatively.

One of the principal objects of the invention is involved in theprovision of an automatic valve mechanism associated with the gearitself for 10 alternatively coupling the usual fluid distributing valveof the gear either with a connection extended thereto from the airsource or with a connection extended thereto from the steam source.

15 Additionally, the invention contemplates improved means foreliminating condensate which may form from time to time in the variousconnections, especially the connection extended from the steam source tothe gear, and improved means 20 for maintaining atmospheric pressure inthe steam line at all times during normal operation of the gear on airpressure.

Still further, the invention has in view the employment of a noveltesting means in order to 25 determine the presence or absence of fluidpressure in the pressure chamber immediately associated with the usualfluid distributing valve.

Other objects of the invention will be understood to the best advantageafter a consideration 30 of the following description of the structureitself in which reference is made to the accompanying drawingsillustrating the preferred embodiment.

Figure 1 is a side elevational view of the general layout including thegear, the gear operat- 35 ing mechanism and the fluid pressureconnections associated therewith, a portion of the locomotive to whichthe structure is applied being indicated in this view by dot and dashlines;

' Figure 2 is a vertical sectional view of the valve 40 mechanismsimmediately associated with the gear; and

Figure 3 is a sectional viewof a detail. In Figure 1 the referencenumeral 6 desighates the outline of a locomotive boiler and 'i 5indicates the outline of the cab. The gear itself, generally indicatedby the letter A, of course, is employed as a servo-motor device foradjusting the setting of the valve mechanism on the locomotive. Thus thepiston rod or trunk 8 of 50 the gear is coupled as by means of link 9with arm l carried by the tumbling shaft H which shaft also carries armI2 which may be coupled in a well known manner with the parts of thevalve gear for reversing the engine and adjust- 55 ing the cut-offthereof. It will be understood,

of course, that the arrangement of the connecting parts such as thoseindicated at 9, II], II and I2 may differ in accordance with theparticular type of valve mechanism with which the reverse gear isassociated.

The piston l3 which is connected with the trunk or rod 8 may be moved incylinder I4 by admitting and exhausting fluid pressure to and fromopposite sides thereof in accordance with the actuation of thecontrolling valve mechanism. At this point it is to be observed that thepresent 10 invention is applicable to power reverse gear arrangements ofa variety of types including types having different main controllingvalve mechanisms. However, in the present illustrative embodiment of thegear itself and main controlling valve therefor, a valve seat I5 isformed at the top of the cylinder I4 (see Figure 2), there being a pairof inlet ports l6 opening through said seat and extended to oppositeends of the cylinder.

A central exhaust port I! also opens through the seat l5 and the threeports are controlled by means of a slide valve [8 having ports l9therein adapted to communicate with ports l6 when the valve is movedfrom its central position. Valve l8 also has a central exhaust cavity 20which serves to couple one or the other of the ports IS with the exhaustport I! depending upon the direction of movement of the valve. The portI! may be connected with an exhaust pipe lla discharging to theatmosphere. A valve chest or housing 2| surrounds valve l8 and may besecured to the cylinder as by means of studs 22. Movement of the valveI8 is controlled as by means of a rocker arm 23 having a journal orbearing 24 in a side wall of the housing 2|. The portion 25 of therocker arm which is disposed inside the housing 2| is connected with thevalve itself and the exterior part 23 is coupled with the combinationlever 26. The lower end of the combination lever is connected as bythelink 21 with a bracket or arm 28 carried on the piston trunk 8 and theupper end of this combination lever is connected with the reach rod 29which extends rearwardly into the cab l of the locomotive and is, inturn, connected with the reverse lever 30 pivoted as at 3| at the baseof the quadrant 32. The features of the main controlling valve andactuating mechanism therefor just referred to are not per se a part ofthe present invention but are briefly described in order to bring outthe cooperative relationship thereof with certain elements and devicesof the invention now to be referred to.

As seen most clearly in Figure 2, an additional Valve device isassociated with the chest 2!. This mice with the position of the valve.

just referred to, but it is to be observed that I contemplate animmediate association of this valve chamber with the main valve chest 2|for reasons which will appear more fully as this description proceeds.

1 With further reference to the valve device at the top of the chest 2|,notethat a pair of ports 35 serve to interconnect the interior of thechest 2| with the cavity 33 through the cylindrical wall thereof. Forreasons presently to be referred to, these ports 35 are spaced from eachother axially of the bore 33. At one end of the cavity 33 an internalshoulder 35:581'V8S as a valve seat between the cavity itself and thepassage 31, which latter preferably has a threaded portion 36 for thereception of pipe 39 extended to the air supply.

At the opposite end of the cavity 33 an enlarged and threaded bore 40 isprovided, and this bore receives a plug device 4! having an internalshoulder 42 which serves as a valve seat between the cavity 33 and thepassage 43. The member 4| is also internally threaded as at 44 toreceive pipe 45 extended to the steam source.

A cylindrical shuttle valve member 46 is fitted in the cavity 33 andthis valve member has tapered end portions 41 and 48 which cooperaterespectively with valve seats 36 and 42 in accord- The valve member 46is preferably made of hard bronze, although other non-oxidizing metalsmay be employed for the purpose, and this is desirable in ensuring freeaction of the valve at all times.

It is further pointed out at this time that the cylindrical portion ofvalve 46, as clearly shown in Figure 2, is of such length that whenpositioned to the right, as in this view, the right hand port 35 iscompletely closed and, in fact, over- -.lapped to an appreciable extent.Stated in another way, the arrangement contemplates a relativeproportioning and location of the valve 46,

the chamber 33 and the ports 35-35 so that with the valve 46 positionedat either end of the cavity 33, the port 35 at that end is closed andover-' lapped by the cylindrical part of the valve. The discussion ofthe operation herebelow will bring out certain advantages of thisconstruction.

Turning again to Figure l, pipe 33 is provided with a lubricating device43 and also with a shutoff valve 50, in advance of the expansion loop39a, after which the pipe is extended for connection with the main airsupply line 5| communicating with the main reservoir 52. From inspectionof Figure 1 it will be noted that the pipe 39 is inclined downwardlyfrom the lubricator 49 to the valve chest on the-gear.

The steam connection 46 is coupled with pipe V 53 extended to'the turret54 or other suitable source of steam and is equipped with'a shut-oil.

valve 55 which valve, as well as valve ill, is located forconvenientaccess inthe cab I of the locomotive. If desired, a reducingvalve may be V introduced'in thesteam line between the turret or othersuitable source and the shut-oil valve 2 55. With regard to pipe 53 itshould be observed that all portions thereof beyond valve 55 areinclined downwardly to the connection 45, and further that an additionaldrain.connection 56 communicates with this system at its low point. 5

Thus the drain connection is extended from the steam supply pipe beyondthe point of communication with the shuttle valve, and this is ofimportance since if it'were located in advance of the communication withthe shuttle valve, when in steam is turned into the supply pipe, as byvalve 55, the condensate formed would be carried into the shuttle valve.The drain connection 56 is further equipped with an automatic drainvalve 51 of a type adapted to remain open when steam 15 is not beingemployed and to close only upon the admission of a substantial quantityof steam to the line 53.

Figure 3 illustrates a valve 5'! suitable for the purpose just referredto. This valve includes a 20 plunger or the like 51a normally held offthe valve seat 511) as by means of a spring 510. An exhaust port 5111 isprovided below the valve seat and, as already mentioned, the valve isarranged so as to remain open when steam is not being 25 employed and toclose upon the admission of a substantial quantity of steam or pressureinto the line 53.

Before considering the operation of the mechanism and the advantagesflowing therefrom, at- 30' tention is called to an additional structuralfea-.

ture which involves the use of a safety device 58 communicating with theinterior of chest 2|. This disposition of the device provides fortesting the fluid pressure supply system to the gear at a 35 pointbetween the shuttle valve mechanism at the top of chest 2| and the maincontrolling valve l8.

In operation, air from the reservoir 52 serves as the usual and normalmotive fluid for op- 40 erating the gear and under normal operatingconditions, therefore, valve 50 will be opened and valve 55 will beclosed. The air pressure in line 39 is thus normally acting on the leftend of the shuttle valve 46 over the entire piston 45 area thereof andserves to retain this valve againstthe seat 42 in which position, itwill be observed. only a relatively small area is exposed .to anypressure which may be present in the steam supply connection. This is aresult of the mate- 50 rially reduced cross sectional area of thepassage through'valve seat 42 as compared with the diameter of thecylindrical cavity 33. From inspection of the drawings it will also beobserved that with the shuttle valve in the right 55 hand position, thepassage for the airthrough chambers 3! and 33 and the left hand port 35are entirely free and unobstructed.

The valve gear is controlled or actuated, of

course, by manipulation of the reverse lever 30 w which moves thecombination lever 26 in one direction or the other and thereby impartsan opposite movement to the valve i6. This, in turn, controls. theadmission and exhaust of air to and from opposite ends of the cylinderand 5 upon movement of the piston and its associated trunk, the link 21serves to return the valve to its mid position in a manner wellunderstood in this art.

Attention is now called to four specific advan- 7o tages of thearrangement-of shuttle valve herein disclosed in connection withretaining the shuttle valve in position to. close the connection to thesteam-line. In the first place, since this 3 shuttle valve iscylindrical in form its movement is of the straight line type and itsaction is in the nature of a piston action which is of importance inensuring positive operation and accurate seating. Secondly, since thesteam connection 45 is normally open to the atmosphere through valve 51,even including times when leakage may occur past the steam shut-ofivalve 55, a differential pressure tending to maintain the steamconnection closed is always assured. In the third place, the arrangementis such that the flow of air through passage 31 and'thence out throughthe left hand port 35 has a tendency to maintain the valve 46 in theposition shown. The action of the air flow tending to move the shuttlevalve to the right and to maintain this valve in the right end of cavity33 is further enhanced by the tapered formation of the end portions ofthe valve itself. Thus, assuming that the valve member is in the lefthand position and is just commencing movement to the right, as soon asthe left hand port 35 has been cracked open, the flow of air inwardlyand then downwardly aids materially in ensuring that the valve willcontinue its movement toward the right to close 01f the steam inletside. A corresponding action will take place when the steam shut-offvalve 55 is opened in order to permit operation of the gear on steampressure. Lastly, the cylindrical portion of the valve 46 being ofconsiderable length closes and overlaps the right hand port 35 so thatno unbalancing effect can occur and, as a result of this, even if theautomatic drain valve were not employed or became stuck in closedposition, the

shuttle valve would not normally be moved from its seat.

The features just above are all of importance in ensuring closure of thesteam side of the shuttle valve during normal operation. The arrangementshown has the further advantage of positively preventing entrance ofsteam into the air supply line 39 under any conditions. If, for somereason, the steam pressure acts to move valve 45 to the left, the pistonaction of this valve positively assures its movement to a position inwhich the left hand port 35 is closed. Thus only one or the other oftheports 35-35 can remain open at any time, and with the left hand port 35closed whenever the right hand port 35 is open, steam can never flowfrom any portion of the shuttle valve mechanism into the air line 39.

If, for any reason, it is desired to operate the gear by steam pressure,the valve 55 is opened and the valve 50 is preferably, although notnecessarily, closed. This permits steam to flow through the connection53 and into the right hand end of the shuttle valve mechanism as aresult of which the valve member 46 will be shifted to the left handposition and the gear can then be operated by steam. Thus, in the eventof failure 'of the normal operating fluid, i. e., the air supply, thegear may still be employed to reverse the engine or adjust the valvegear setting.

Upon admission of steam into the connection 53, of course, the pressurethereof in the drain pipe 56 closes the automatic valve 51.

The safety device, such as the test cook or equivalent device 58, inbeing located in the manner referred to above and illustrated in thedrawings, has several special advantages including use thereof as ameans of introducing a liquid such as kerosene or other cleansing orlubricating liquid, in on top of the fluid pressure controlling valve inorder to clean the valve seat oreliminate gumming or for lubricationpurposes. Additionally, the location of the test cock between theshuttle valve and the main fluid controlling valve makes possibletesting for pressure in the chest 2| when the gear is to be 5 operatedeither on the air supply or on the steam supply. Thus, as a practicalconsideration, it will be noted that a workman in a round-house or shopneed not climb. into the cab in order to close either one or both of theshut-01f valves 50 and 55 when he is working on the gear. The importanceof this will appear to better advantage if it be considered that thegreat power of the reverse gear has heretofore caused considerablemechanical and physical damage in instances where portions of thereverse gear or the associated valve gear are being dismantled. With thepresent arrangement, the workman may open the device 58 whenever work isbeing done on the valve gear or the reverse gear itself and an audiblewarning, will be given in the event that either the steam line or theair line is'inadvertently opened or in the event that pressure builds upas a result of a leaky valve.

Still further, it may be desirable at" times to 5 test the steam supplyto the gear without actually passing any steam into the gear cylindersince the employment of steam in the gear is disadvantageous for variousreasons, and is resorted to only in the event of failure of the airsupply. A periodic test of the steam supply, however, is highlydesirable to ensure that it will be avai1- able when desired, and thismay be done by opening the test cock with the assurance that the entiresteam supply system is functioning proper- 1y. In fact, this device maybe employed to test every joint in the entire air supply and steamsupply systems, including those immediately associated with the valvechest 2!, such as indicated at 38 and 44. Finally, the location of the40 test cock as indicated is advantageous since it will give anindication as to whether any of the pipes in the fluid pressure supplysystem are clogged or frozen or leaking, or whether the shuttle-valve isstuck or frozen.

Another advantage of the general layout and arrangement of piping andthe like flows from the self-draining arrangement of the cavities in theshuttle valve arid from the inclination of the air and steam pipes asdescribed above. Any condensate which may form in the steam pipe as wellas in the short connection 45 and the immediately associated passage 43will drain downwardly through the pipe 56 and valve 51, this beingaccomplished without the danger of blowing condensate into the shuttlevalve mechanism when steam is turned into the line 53 or when anyappreciable leakage occurs.

The arrangement of the shuttle valve in immediate association with thevalve gear itself, 60 and preferably within a chamber formed in a partof the chest 2!, ensures operation of the gear on either fluid which maybe available in the event of failure of the piping for the other fluideven at the threaded connection thereof with the chest 2|. This unitaryor integral arrangement of the valve chambers for the main distributingvalve and the shuttle valve is of further advantage since it makespossible convenient adaptation of the invention to reverse 7 gearequipment already in service.

In accordance with a the foregoing, air and steam supply connections areindependently extended to the gear and in the event of failure of theair supply achange to steam may be made member for a fluid pressureoperated power reverse gear, said member having a dome-like cavitytherein for the controlling valve 01 the gear, said member furtherhaving a cylindrical valve cavity therein adapted to receive a shuttlevalve, the cylindrical cavity having its axis extended approximatelytangent to the wall of the dome-like cavity and having a port at eachend for connection with difierent sources of 'operating fluid for thegear, and said member having portage interconnecting the two cavitiesad- 10 jacent the point of approximate tangency.

' GEORGE H. ZOUCK

